Hi all, I have created KIP-286: producer.send() should not block on metadata update. See https://cwiki.apache.org/confluence/display/KAFKA/KIP-286%3A+producer.send%28%29+should+not+block+on+metadata+update .
The KIP intends to improve user-experience of producer.send() when metadata is not available. It is related but different from the previous discussion in KAFKA-3539 in the sense that user still has the option of letting producer.send() block on full producer queue. Comments are welcome! Thanks, Dong